Pencil-sharpener.



C. S. BURTON.

' PENCIL SHARPENEB.

APPLICATION FILED DEC.22, 1913- 1 ,2653'431 v Patented May 14, 1918.

- ,E 2 SHEETS-SHEET l- @WIQM v C. S. BURTON.

PENCIL SHARPENER.

APPUCATION man 020.22. I913.

Patented May14, 1918.

2 SHEETS-SHEET 2 CHARLES S. BURTON, OF OAK PARK, ILLINOIS.

PENCIL-SHARPENEB.

Application filed December 22, 1913.

To all whom it may concern:

Be it known that I, CHARLES S. Borrow, a citizen of the United States, residing at Oak Park, in the county of Cook and State of lllinois, have invented new and useful Improvements in Pencil-Sharpeners, of which the following is a specification, reference being had to the accompanying drawings, forming a part thereof.

The purpose of this invention is to provide an improved mechanism for sharpening pencils and similar work involving the production of a conical or tapered point by cutting. It consists in the elements and features of construction shown and described as indicated in the claims.

In the drawings Figure l is a side elevation of a machine embodying this invention.

Fig. 2 is a top plan view of the same.

Fig. 3 is an end elevation.

Fig. is a section at the line lfon Fig. 5.

F ig. 5 is a section at the line 5--5 on Fig. 2, through the axis of the pencil scat.

Fig. 6 is a section at the line 6-6 on Fig. 5.

Fig. 7 is a side view of one of the cutters.

Figs. 8 and 9 are opposite end views of the same.

Figs. 10 and 11 are diagrammatic views to illustrate the law of formation of the cutter, Fig. 10 being an end view of a skeleton of a cutter and Fig. 11 a side view of such skeleton.

The intention of'the construction shown in the drawings is to provide revolving cutters having each a plurality of perfectly straight cutting edges, so arranged about the axis of revolution of the cutter as to operate with a draw out upon the object properly presented in their path, and adapt ed to have in this respect substantially the same effect and mode of action as is familiarly obtained by cutters having spiral cutting edges. As is obvious, a difficulty in the employment of cutters having spiral cutting edges is the impossibility of sharpening or re-grinding them without employing complicated machinery specially designed fer the purpose. The production of a cutter which will operate in the same manner for cutting by means of a perfectly straight edge obviates or greatly reduces this difiiculty.

The form of the cutter embodied in this Specification of Letters Patent.

Fatented May an, 1918.

Serial No. 808,069.

invention is that which would result from mounting upon the surfaces of a regular polygonal prism flat knives with their cut ting edges in the plane of the face on which they are mounted and at an acute angle to the edges of the prism, so that the form described by the revolution about its axis of the prism with the knives so mounted upon it would be conoidal with the surface concave in axial section. Figs. 10 and 11 present respectively an end View, or a view in the direction of the axis, and a side view of what may be called a skeleton cutter produced in the manner above described. The practical cutter is shown in the other figures, being a solid steel body such as would result from filling up the interspaces between the polygonal prism and the knives mounted on it, as above described, so as to leave the knife edges properly protruding and with proper clearance for cutting. This form must be carefully distinguished from a mere conical body, either with cutting edges straight, which could only be the case when these edges are in axial planes, or with the cutting edges oblique and lying in the surface of the cone, which results in such edges being spiral or elliptical, and therefore curved and not straight edges.

In the construction shown and preferred, two cutters, A,A, of the solid form above described are mounted for rotation about their respective axes in a frame, B, which is in turn mounted in a frame, C, for rotation about an axis which has no plane in common with either of the cutter axes. The cutters are positioned in the frame, B, with their axes in such relation to each other that they both describethe same path in the rotation of the frame, B, about its axis in the frame, C; and the planes containing said axes respectively, and intersecting in a line which connects the points of nearest ap proach of said axes, are at an angle to each other approximately equal to the angle of taper of the cutters, so that the volumes de scribed by the two cutters in their rotation about their respective axes are as nearly tangent to each other as their form, which is concavely curved in axial section, permits. For mounting the frame, B, in the frame, C, as described, the frame, B, is provided with trunnions, B and B the trunnion, B being hollow for journaling on a bushing sleeve, D, which is mounted in the frame, C, and adapted to serve as the seat or guide pencil seat, a rotating cutter having straight edges, each positioned in a plane parallel to the axis of rotation, and each in its respective plane diverging from a line therein parallel to the axis, and means for rotating the cutter about its axis in the direction to carry the end of each cutting edge which is more distant from the axis in advance of the other end.

A pencil-sharpening machine comprising a frame having a pencil seat, a second frame mounted in the first for rotation about the axis of the pencil seat; a cutter having its cutting edges departing farther and farther from the axis of the cutter from end to end, said cutter being mounted in the sec- 0nd frame for rotation about an axis situated in a line non-intersecting with the line containing the axis of the pencil seat; means for rotating the second frame and steering means for simultaneously rotating the cutter about its axis in said frame in the direction for carrying the ends of the cutting edges which are remote from the cutter axis in advance of their opposite ends.

6. In a pencil sharpening machine or the like, a milling device comprising a revolving carrier, a milling cutter mounted in said carrier for independent rotation therein, said milling cutter having its axis of rotation so disposed as to have no plane in common with the axis of said carrier and having its cutting edges departing farther and farther from the axis from end to end, and means for revolving said milling cutter.

7. In a pencil sharpening machine or the like, a means for guiding a pencil, a milling device comprising a revolving carrier, a milling cutter mounted in said carrier for independent rotation therein, said milling cutter having its axis of rotation so disposed as to have no plane in common With the axis of said carrier and having its cutting edges departing farther and farther from the axis from end to end, and means for giving said milling cutter a planetary movement about said pencil guide.

In testimony whereof I have hereunto set my hand at Chicago, Illinois, this 19th day of December, 1913.

CHARLES S. BURTON.

Witnesses:

EDNA M; MAoIN'rosH, M. Gnnrnnon Any.

Copies or this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

